how to get some documents from one xml - xslt

Question

I would like to get distinct documents from my xml on multiple levels.
My xml file:
<?xml version="1.0" encoding="UTF-8"?>
<document>
<line id="0">
<Info><![CDATA[Header]]></Info>
<documentNUM><![CDATA[DOC1]]></documentNUM>
<Code><![CDATA[AS22]]></Code>
</line>
<line id="1">
<Info><![CDATA[Line]]></Info>
<Position><![CDATA[1]]></Position>
<Number><![CDATA[7361]]></Number>
</line>
<line id="2">
<Info><![CDATA[Line]]></Info>
<Position><![CDATA[2]]></Position>
<Number><![CDATA[7362]]></Number>
</line>
<line id="3">
<Info><![CDATA[Header]]></Info>
<documentNUM><![CDATA[DOC2]]></documentNUM>
<Code><![CDATA[AS22]]></Code>
</line>
<line id="4">
<Info><![CDATA[Line]]></Info>
<Position><![CDATA[1]]></Position>
<Number><![CDATA[3623]]></Number>
</line>
<line id="5">
<Info><![CDATA[Header]]></Info>
<documentNUM><![CDATA[DOC1]]></documentNUM>
<Code><![CDATA[AS22]]></Code>
</line>
<line id="6">
<Info><![CDATA[Line]]></Info>
<Position><![CDATA[1]]></Position>
<Number><![CDATA[3623]]></Number>
</line>
</document>
From this xml I should get two documents,
for it I use key function:
<xsl:key name="kNext" match="line[starts-with(Info,'H')]" use="concat(starts-with(Info,'H'), '+', documentNUM)"/>
And for both documents 3 and 1 lines.
Needed result:
<result>
<Group>
<Message>
<document>
<documentNUM>DOC1</documentNUM>
<Lines>
<Line>
<LineNumber>1</LineNumber>
<Number>7361</Number>
<Code>AS22</Code>
</Line>
<Line>
<LineNumber>2</LineNumber>
<Number>7362</Number>
<Code>AS22</Code>
</Line>
<Line>
<LineNumber>3</LineNumber>
<Number>3623</Number>
<Code>AS22</Code>
</Line>
</Lines>
</document>
</Message>
</Group>
<Group>
<Message>
<document>
<documentNUM>DOC2</documentNUM>
</document>
<Line>
<LineNumber>1</LineNumber>
<Number>3623</Number>
<Code>AS22</Code>
</Line>
</Lines>
</Message>
</Group>
</result>
I'm stuck to finding lines. For both documents calculate the same lines. Please give me some advice how to get correct answer.
P.S. Please correct my question if it needed.

Answer 1

Here is a complete XSLT 1.0 solution:
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:key name="kFollowing" match="line[not(documentNUM)]"
use="generate-id(preceding-sibling::line
[documentNUM]
[1]
)"/>
<xsl:key name="kLineByDocNum" match="line"
use="documentNUM"/>
<xsl:template match=
"line
[documentNUM
and
generate-id()
=
generate-id(key('kLineByDocNum', documentNUM)[1])
]">
<Group>
<Message>
<document>
<documentNUM>
<xsl:value-of select="documentNUM"/>
</documentNUM>
<Lines>
<xsl:apply-templates mode="inGroup" select=
"key('kLineByDocNum', documentNUM)"/>
</Lines>
</document>
</Message>
</Group>
</xsl:template>
<xsl:template match="line" mode="inGroup">
<xsl:apply-templates mode="inGroup2"
select="key('kFollowing', generate-id())">
<xsl:with-param name="pCode" select="Code"/>
</xsl:apply-templates>
</xsl:template>
<xsl:template match="line" mode="inGroup2">
<xsl:param name="pCode"/>
<xsl:variable name="vcurDocNum" select=
"preceding-sibling::line
[documentNUM][1]
/documentNUM
"/>
<xsl:variable name="vPos" select=
"count(preceding-sibling::line
[not(documentNUM)]
[preceding-sibling::line
[documentNUM][1]
/documentNUM
=
$vcurDocNum
]
) +1"/>
<Line>
<LineNumber><xsl:value-of select="$vPos"/></LineNumber>
<xsl:copy-of select="Number"/>
<Code><xsl:value-of select="$pCode"/></Code>
</Line>
</xsl:template>
<xsl:template match="text()"/>
</xsl:stylesheet>
when this transformation is applied on the provided XML document:
<document>
<line id="0">
<Info>Header</Info>
<documentNUM>DOC1</documentNUM>
<Code>AS22</Code>
</line>
<line id="1">
<Info>Line</Info>
<Position>1</Position>
<Number>7361</Number>
</line>
<line id="2">
<Info>Line</Info>
<Position>2</Position>
<Number>7362</Number>
</line>
<line id="3">
<Info>Header</Info>
<documentNUM>DOC2</documentNUM>
<Code>AS22</Code>
</line>
<line id="4">
<Info>Line</Info>
<Position>1</Position>
<Number>3623</Number>
</line>
<line id="5">
<Info>Header</Info>
<documentNUM>DOC1</documentNUM>
<Code>AS22</Code>
</line>
<line id="6">
<Info>Line</Info>
<Position>1</Position>
<Number>3623</Number>
</line>
</document>
the wanted, correct result is produced:
<Group>
<Message>
<document>
<documentNUM>DOC1</documentNUM>
<Lines>
<Line>
<LineNumber>1</LineNumber>
<Number>7361</Number>
<Code>AS22</Code>
</Line>
<Line>
<LineNumber>2</LineNumber>
<Number>7362</Number>
<Code>AS22</Code>
</Line>
<Line>
<LineNumber>3</LineNumber>
<Number>3623</Number>
<Code>AS22</Code>
</Line>
</Lines>
</document>
</Message>
</Group>
<Group>
<Message>
<document>
<documentNUM>DOC2</documentNUM>
<Lines>
<Line>
<LineNumber>1</LineNumber>
<Number>3623</Number>
<Code>AS22</Code>
</Line>
</Lines>
</document>
</Message>
</Group>

Answer 2

This looks like a grouping problem. If you have XSLT 2.0 available, use for-each-group / group-starting-with. Then you don't need a key:
<result>
<xsl:for-each-group select="line"
group-starting-with="line[starts-with(Info,'H')]">
<Group>
<Message>
<document>
<documentNUM>
<xsl:value-of select="current-grouping-key()/documentNUM" />
</documentNUM>
</document>
<xsl:apply-templates select="current-group()
[not(starts-with(Info, 'H'))]" />
etc.
If you want more detail, let me know.